In addition to optical methods for particle measurement, particle sensors are known, which measure the particle content in an exhaust gas via a conductivity measurement of particles accumulated on a surface between two measuring electrodes. In order to minimize the influence of condensed moisture on the conductivity, for example, these conductivity measurements are performed at a higher, constant temperature. Then, such particle sensors are periodically regenerated by thermal and/or electrical methods, in which accumulated particles are removed by so-called “burn off.”
The precision of the measurement is typically limited, in particular after the regeneration and in the case of detection of small particle quantities, because particle bridges must first form between the measuring electrodes for the conductivity measurement.
German Patent Application No. DE 101 33 384 describes a particle sensor, which has a carrier layer having an integrated heating element as well as a second layer having printed-on measuring electrodes.